Collaborative Spam Filtering

Thanks to the previous post I came across Cloudmark. This company operates a collaborative spam filtering service. A user downloads a button bar, which will be added to Outlook. This button-bar allows a user to block or unblock an email-message. If a users blocks a message, it is removed from his email-box and a message is sent to the central Cloudmark server. When a user downloads his email messages, his messages are checked against the central server and if needed they are tagged as spam. The service also ranks the spam-reporters (users) trustworthiness. Thus only emails spammed by trusted spam-reporters will be removed.

The service also has a service for businesses. Any email-address from a registered business will get on a whitelist. The business will however get a feedback on the reaction of the users and might end up as spam(?).

From a service point of view I see this service as a directory of email (or maybe just the hashes), which has been labelled as spam. I guess they remove non-spam email (hashes). Users can read the labels and submit labels. Businesses can un-label messages and I guess they use the labeling services of blacklists as well.

It does remind me of what Richard Soderberg has been saying.